Currently, a trifunctional silane is mainly used as a raw material of a commercial silane-based coating agent, and a polysiloxane having moderate hardness and flexibility is formed by such a trifunctional silane. However, a hard coating property of a film of a trifunctional silane is not sufficient. Therefore, a tetrafunctional silane and colloidal silica are mixed with the trifunctional silane to compensate the hard coating property, but there is a problem that, if the film is cured, the film easily cracks and adhesiveness becomes worse.
As a silane-based coating agent, for example, an antifouling film forming composition containing a trifunctional alkoxysilane compound having an epoxy group (patent document 1) is used. In addition, a silane-based coating agent containing a photocatalyst is also proposed, and a film is cured by using a photo-acid-generating agent, a cross-linking agent, a curing catalyst, or the like (for example, patent documents 2 and 3). Furthermore, a silane-based organic-inorganic complex gradient material having a component gradient structure in which the content rate of a metal-based compound in the material continuously changes in the depth direction from the surface of the material is also proposed (for example, patent document 4).
Patent document 5 discloses that, by irradiating an organic silicon compound with ultraviolet rays in the presence of a photosensitive compound, an organic-inorganic complex in which the surface has very high hardness and the inside and the back surface side have appropriate hardness and which excels in adhesiveness to a base substance can be provided, and furthermore, patent document 6 discloses that, by blending an acrylate-based resin that is an ultraviolet curable resin in a polysiloxane-based organic-inorganic complex, an organic-inorganic complex in which the surface has very high hardness and which excels in adhesiveness to a base substance and humidity resistance can be provided.
Conventionally, a problem has been that, in a decoratively-deposited plastic container or the like, poor adhesion often occurs between a metal deposited film and the plastic container, thereby causing peeling of the deposited film. Therefore, in order to achieve good adhesiveness, an anchor coat (base film) is needed between the metal deposited film and the plastic container. Currently, as the anchor coat, one layer is insufficient, and a two-layer structure with a layer (A) having good adhesiveness to the plastic container and a layer (B) having good adhesiveness to both the above-described (A) and the metal deposited film is needed. However, a problem was that manufacturing cost is increased and a high degree of skill is required by increasing the number of layers. Therefore, an anchor coat agent that can be used as an anchor coat for a plastic container and an inorganic film by one layer has been studied, but an organic-inorganic complex film disclosed in patent document 6 requires UV irradiation, and a problem was that a uniform UV irradiation technique for a three-dimensional plastic container is needed.